info_passwd.c revision 310490 
1/*
2 * Copyright (c) 1997-2014 Erez Zadok
3 * Copyright (c) 1990 Jan-Simon Pendry
4 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Jan-Simon Pendry at Imperial College, London.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *
36 * File: am-utils/amd/info_passwd.c
37 *
38 */
39
40/*
41 * Get info from password "file"
42 *
43 * This is experimental and probably doesn't do what you expect.
44 */
45
46#ifdef HAVE_CONFIG_H
47# include <config.h>
48#endif /* HAVE_CONFIG_H */
49#include <am_defs.h>
50#include <amd.h>
51
52#define	PASSWD_MAP	"/etc/passwd"
53
54/* forward declarations */
55int passwd_init(mnt_map *m, char *map, time_t *tp);
56int passwd_search(mnt_map *m, char *map, char *key, char **pval, time_t *tp);
57
58
59/*
60 * Nothing to probe - check the map name is PASSWD_MAP.
61 */
62int
63passwd_init(mnt_map *m, char *map, time_t *tp)
64{
65  *tp = 0;
66
67  /*
68   * Recognize the old format "PASSWD_MAP"
69   * Uses default return string
70   * "type:=nfs;rfs:=/${var0}/${var1};rhost:=${var1};sublink:=${var2};fs:=${autodir}${var3}"
71   */
72  if (STREQ(map, PASSWD_MAP))
73    return 0;
74  /*
75   * Recognize the new format "PASSWD_MAP:pval-format"
76   */
77  if (!NSTREQ(map, PASSWD_MAP, sizeof(PASSWD_MAP) - 1))
78    return ENOENT;
79  if (map[sizeof(PASSWD_MAP)-1] != ':')
80    return ENOENT;
81
82  return 0;
83}
84
85
86/*
87 * Grab the entry via the getpwname routine
88 * Modify time is ignored by passwd - XXX
89 */
90int
91passwd_search(mnt_map *m, char *map, char *key, char **pval, time_t *tp)
92{
93  char *dir = NULL;
94  struct passwd *pw;
95
96  if (STREQ(key, "/defaults")) {
97    *pval = xstrdup("type:=nfs");
98    return 0;
99  }
100  pw = getpwnam(key);
101
102  if (pw) {
103    /*
104     * We chop the home directory up as follows:
105     * /anydir/dom1/dom2/dom3/user
106     *
107     * and return
108     * rfs:=/anydir/dom3;rhost:=dom3.dom2.dom1;sublink:=user
109     * and now have
110     * var0:=pw-prefix:=anydir
111     * var1:=pw-rhost:=dom3.dom2.dom1
112     * var2:=pw-user:=user
113     * var3:=pw-home:=/anydir/dom1/dom2/dom3/user
114     *
115     * This allows cross-domain entries in your passwd file.
116     * ... but forget about security!
117     */
118    char *user;
119    char *p, *q;
120    char val[MAXPATHLEN];
121    char rhost[MAXHOSTNAMELEN];
122    dir = xstrdup(pw->pw_dir);
123
124    /*
125     * Find user name.  If no / then Invalid...
126     */
127    user = strrchr(dir, '/');
128    if (!user)
129      goto enoent;
130    *user++ = '\0';
131
132    /*
133     * Find start of host "path".  If no / then Invalid...
134     */
135    p = strchr(dir + 1, '/');
136    if (!p)
137      goto enoent;
138    *p++ = '\0';
139
140    /*
141     * At this point, p is dom1/dom2/dom3
142     * Copy, backwards, into rhost replacing
143     * / with .
144     */
145    rhost[0] = '\0';
146    do {
147      q = strrchr(p, '/');
148      if (q) {
149	xstrlcat(rhost, q + 1, sizeof(rhost));
150	xstrlcat(rhost, ".", sizeof(rhost));
151	*q = '\0';
152      } else {
153	xstrlcat(rhost, p, sizeof(rhost));
154      }
155    } while (q);
156
157    /*
158     * Sanity check
159     */
160    if (*rhost == '\0' || *user == '\0' || *dir == '\0')
161      goto enoent;
162
163    /*
164     * Make up return string
165     */
166    q = strchr(rhost, '.');
167    if (q)
168      *q = '\0';
169    p = strchr(map, ':');
170    if (p)
171      p++;
172    else
173      p = "type:=nfs;rfs:=/${var0}/${var1};rhost:=${var1};sublink:=${var2};fs:=${autodir}${var3}";
174    xsnprintf(val, sizeof(val), "var0:=%s;var1:=%s;var2:=%s;var3:=%s;%s",
175	      dir+1, rhost, user, pw->pw_dir, p);
176    dlog("passwd_search: map=%s key=%s -> %s", map, key, val);
177    if (q)
178      *q = '.';
179    *pval = xstrdup(val);
180    return 0;
181  }
182
183enoent:
184  XFREE(dir);
185
186  return ENOENT;
187}
188